Zend_Mail_Storage_Pop3 はデータを表示できません

<br />
$pop = new Zend_Mail_Storage_Pop3(array('host'=>'smtp.163.com',<br />
		                                        'user'=>'aaa@163.com',<br />
		                                        'password'=>'aaa',<br />
		                                        'port'=>465,<br />
		                                        'ssl'=>'ssl'));<br />
		<br />
		echo $pop->countMessages().' aaaaa<br/>';<br />
		foreach ($pop as $message) {<br />
            echo "Mail from '{$message->from}': {$message->subject}\n";<br />
        }<br />
        echo 'ccccccc<br/>';<br />
<br />

<br />
Application error<br />
Exception information:<br />
Message: last request failed <br />